1. Field of the Invention
The present invention relates to a hard disk drive, and more particularly, to an apparatus to support an actuator of a hard disk drive to pivot in a radius direction of a hard disk.
2. Description of the Related Art
In general, a hard disk drive which is an auxiliary memory device of a computer includes a hard disk that rotates at a high speed by a spindle motor installed inside the hard disk drive, and an actuator that has a magnetic head to record/reproduce data on/from a track of the hard disk.
The actuator is installed to pivot around a predetermined pivot shaft. A bobbin and a coil installed at one end of the actuator is moved by an operation of a voice coil motor so that the magnetic head installed at the other end of the actuator moves to a desired track position and records/reproduces data on/from the hard disk. Here, the magnetic head which moves above both sides of a hard disk is lifted by a flow of air on a surface of the hard disk as the hard disk rotates at a high speed and moves, maintaining a fine gap with the hard disk. When the hard disk drive stops or electric power is cut off during the above operation, the actuator moves to a parking area located in an inner circumferential side of the hard disk, so that damage to the hard disk due to contact with the disk and the magnetic head is prevented.
FIG. 1 shows a conventional hard disk drive operating as described above. FIG. 2 illustrates a vertical structure of an actuator supporting apparatus adopted in the hard disk drive of FIG. 1.
Referring to FIG. 1, a hard disk drive includes a housing 1 having a base 2 and a cover 3. A hard disk 4 in which predetermined information is recorded or reproduced, and an actuator 6 having a magnetic head 5 to record and reproduce information are installed in the housing 1. Also, a voice coil motor 7 to pivot the actuator 6 by an electrostatic force is installed in the housing 1. The actuator 6 includes a suspension 8 to support the magnetic head 5 to face a recording surface of the hard disk 4, and an actuator arm 9 to support an end portion of the suspension 8 and to pivot by the voice coil motor 7 in a radial direction of the hard disk 4. The actuator arm 9 is supported to pivot by an actuator supporting apparatus 10 installed in the housing 1.
The actuator supporting apparatus 10, as shown in FIG. 2, includes a pivot bearing 14 including an inner ring 11, an outer ring 12, and a rolling member 13 interposed between the inner ring 11 and the outer ring 12, to support the actuator arm 9 to pivot. The pivot bearing 14 is fixed on an upper surface of the base 2 by a first coupling member 15 coupled to a mounting boss 2a vertically extended from the base 2. A damper 17 interposed between the cover 3 and the first coupling member 15 is fixed to the first coupling member 15 by a second coupling member 16 that is complementarily coupled to the first coupling member 15. Here, the damper 17 includes a plate 18 having a predetermined strength and an adhesive layer 19 deposited on the plate 18. The damper 17 adheres to the cover 3 by an adhesive force of the adhesive layer 19. Also, the adhesive layer 19 buffers vibrations and impacts transferred between the housing 1 and the actuator arm 9.
However, in the above conventional actuator supporting apparatus 10, due to accumulated manufacture allowance of constituent parts of the actuator supporting apparatus 10, as shown in FIG. 2, a gap may occur between the damper 17 and the first coupling member 15. Here, when the second coupling member 16 is coupled to the first coupling member 15, the damper 17 interposed between the first coupling member 15 and the second coupling member 15 receives a force acting downward and is pushed toward the first coupling member 15 and closely fixed thereto. Thus, a coupling force between the damper 17 and the cover 3 adhering to each other becomes weak so that the coupling between the damper 17 and the cover 3 is loose. The loose coupling between the damper 17 and the cover 3 deteriorates a feature of buffering vibrations and impacts by the damper 17. Also, the adhesive force of the adhesive layer 19 decreases by a change in environment, in particular, at a high temperature, so that the feature of buffering vibrations and impacts by the damper 17 is further lowered. Also, the lowering of the coupling force between the cover 3 and the damper 17 lowers a structural strength of the actuator supporting apparatus 10 which may deteriorate reliability of a product.
Therefore, an actuator supporting apparatus having a new structure is needed which may not only support the actuator to pivot, but also buffer vibrations and impacts between the housing and the actuator arm, regardless of accumulated allowance of a product or a change in the external environment.